This invention relates to aspiration devices for body fluids. More particularly, it relates to a uniform suction device which, after preloading, is operable without external vacuum means by the opening of a valve member and will provide a uniform suction throughout the movement of the device.
Apparatus for collecting body fluids are described in U.S. Pat. No. 3,200,813 as well as in U.S. Pat. Nos. 3,382,856 and 3,706,305. All of these devices relate to either vacuumized syringe units or units which contain one or more compartments for the collection of fluids. In U.S. Pat. No. 2,646,042 a syringe-type aspirating unit is utilized in conjunction with a complex pressure equalizing apparatus as well as a syringe having concentric plungers.
None of the prior art teaches a double-headed piston member which is operable at one end in a syringe barrel and at the other end in a telescoping member receivable in the syringe barrel to effect a vacuum in the syringe which is releasable by mere manipulation of a valve member. All of the prior art units are either concerned with prevacuumized containers or collecting samples in a multiplicity of units which are pierced by a cannula member. None of the prior art devices teaches a simplified unit which can aspirate body fluids from relatively large body cavities by means of a uniform suction which can be created in the unit itself.
It is an advantage of the present invention to provide a novel aspirating device which will afford uniform suction over the length of the piston stroke effecting the vacuum. Other advantages are an aspirating unit which is capable of one-handed operation by means of the mere movement of a valve member; an aspirating unit which can aspirate relatively large volumes of fluid from relatively large body cavities; an aspirating unit which is completely disposable; an aspirating unit wherein the partial vacuum is created in the unit itself prior to its use and a uniform suction device which can be readily regulated by operation of a valve; a uniform aspirating device which can be interconnected to a large length of tubing for aspirating body fluids from a uterus.